System status message protocol

diff --git a/common/sysconf.c b/common/sysconf.c
new file mode 100644 (file)
index 0000000..fac3c06
--- /dev/null
+++ b/common/sysconf.c
@@ -0,0 +1,134 @@
+/* systat.c
+
+   System status watcher...
+
+   !!!Boy, howdy, is this ever not guaranteed not to change!!! */
+
+/*
+ * Copyright (c) 1997 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#ifndef lint
+static char copyright[] =
+"$Id: sysconf.c,v 1.1 1997/09/16 18:15:44 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+
+int systat_initialized;
+int systat_fd;
+
+void systat_startup (handler)
+       void (*handler) PROTO ((struct systat_header *, void *));
+{
+       struct sockaddr_un name;
+       static int once;
+
+       /* Only initialize systat once. */
+       if (systat_initialized)
+               error ("attempted to reinitialize systat protocol");
+       systat_initialized = 1;
+
+       systat_fd = socket (AF_UNIX, SOCK_STREAM, 0);
+       if (systat_fd < 0)
+               error ("unable to create systat socket: %m");
+
+       /* XXX for now... */
+       name.sun_family = PF_UNIX;
+       strcpy (name.sun_path, "/var/run/systat");
+       name.sun_len = ((sizeof name) - (sizeof name.sun_path) +
+                       strlen (name.sun_path));
+
+       if (connect (systat_fd, (struct sockaddr *)&name, name.sun_len) < 0) {
+               if (!once)
+                       warn ("can't connect to systat socket: %m");
+               once = 1;
+               close (systat_fd);
+               systat_initialized = 0;
+               add_timeout (cur_time + 60, systat_restart, handler);
+       } else
+               add_protocol ("systat", systat_fd, systat_message, handler);
+}
+
+void systat_restart (v)
+       void *v;
+{
+       void (*handler) PROTO ((struct systat_header *, void *)) = v;
+
+       systat_startup (handler);
+}
+
+void systat_message (proto)
+       struct protocol *proto;
+{
+       struct systat_header hdr;
+       int status;
+       char *buf;
+       void (*handler) PROTO ((struct systat_header *, void *));
+
+       status = read (systat_fd, &hdr, sizeof hdr);
+       if (status < 0) {
+               warn ("systat_message: %m");
+             lose:
+               add_timeout (cur_time + 60, systat_restart, proto -> local);
+               remove_protocol (proto);
+               return;
+       }
+       if (status < sizeof (hdr)) {
+               warn ("systat_message: short message");
+               goto lose;
+       }
+
+       if (hdr.length) {
+               buf = malloc (hdr.length);
+               if (!buf)
+                       error ("systat_message: can't buffer payload");
+               status = read (systat_fd, buf, hdr.length);
+               if (status < 0)
+                       error ("systat_message payload read: %m");
+               if (status != hdr.length)
+                       error ("systat_message payload: short read");
+       } else
+               buf = (char *)0;
+
+       /* Call the handler... */
+       if ((handler = proto -> local))
+               (*handler) (&hdr, buf);
+
+       if (buf)
+               free (buf);
+}